Surgical ring featuring a reversiblediameter remote control system

ABSTRACT

The invention involves a surgical ring, designed to be implanted around biological organs comprising a pouch or a duct, so as, on the one hand, to form a closed loop between these two extremities ( 1, 2 ), thus forming a first ( 1 ) and a second ( 2 ) extremity and, on the other hand, to reduce the diameter of the opening of said organ when it is tightened by the ring, said ring comprising a system for reversibly controlling the variation in its diameter, characterized in that said system comprises a flexible fillform element ( 4 ), inserted longitudinally with possibility of sliding into the material constituting the body of the ring between the first ( 1 ) and second ( 2 ) extremities, so as to define a fixed portion ( 5 ) connected to the first extremity ( 1 ) and a free portion ( 7 ) associated with an actuator ( 8 ) mounted on the ring near the second extremity ( 2 ).

FIELD OF THE INVENTION

The present invention relates to the technical field of surgicalimplants designed to be implanted in the body of a patient, aroundbiological organs having a pouch or duct, and, more specifically, togastric rings concepted to treat obesity by implantation of a flexiblegastric ring. This ring is designed to form a closed loop around thestomach, in order to reduce the diameter of the opening of the stoma.The invention relates more specifically to the remote-controlgastroplasty rings, involving no invasive operation whatsoever after itsinstallation.

The present invention involves a surgical ring designed to be implantedin the body of a patient around biological organs comprising a pouch ora duct. On the one hand this forms a closed loop between its twoextremities. This forms, respectively, a first and second extremity and,on the other hand, reduces the diameter of the opening of said organwhen it is constricted by the ring, said ring comprising a system forprecise and reversible control of the variation of the diameter of thering. The control system comprises a flexible filiform element.

The invention involves, more specifically, a gastroplasty ring, but itcan also involve a ring designed to be used to treat urinary or fecalincontinence (artificial sphincter), or even a ring conceived toregulate blood flow in blood vessels for example; this list is by nomeans exhaustive.

More specifically, the present invention involves a remote-controlgastroplasty ring that avoids all invasive surgical re-intervention foradjusting the ring's diameter. This ring is then integrated into asystem of restriction and remote control of the ingestion of food intothe stomach of a patient. It consists of a gastric ring fitted with anactuator connected to a receiving antenna for receiving a controlsignal, as well as an emitting antenna that is arranged outside thepatient to send a control signal to the receiving antenna, then to theactuator.

In its preferred application, the ring in compliance with the inventionis controlled by radio frequency. The actuator is, on the one hand,linked to the receiving antenna by a receiving circuit, in which saidantenna is installed and, on the other hand, comprises an electriccontrol case linked to an emitting antenna.

BACKGROUND OF THE INVENTION

Surgical intervention is already practiced on patients afflicted withextremely severe obesity (morbid obesity), i.e. in the case of thepatient whose weight exceeds, for example the ideal weight of at least50 kg, by implanting gastroplasty rings in such patients. Suchinterventions allow not only a series of serious health problems,arising from such overweight, to be avoided, but also and especially toavoid a certain, early death of such patients.

In fact, it is a given fact that patients suffering from morbid obesitysee their life expectancy significantly reduced, by at least ten tofifteen years, all the while creating significant psychological burdens.Moreover, a whole series of additional health phenomena are implicated.Their incidence has been implicated in the appearance of additionalillnesses such as cardio-vascular illnesses, or even those such ashypertension, diabetes or even severe arthritis.

It is also a given fact that, for such patients, treatments based onstrict diets combined with a series of physical exercises, alsoassociated with behavior modification, specifically nutritional, arepoorly adapted, even if these treatment methods are acknowledged to bethe safest.

This is the reason why effective, long-term treatments for morbidobesity call for surgical intervention.

In general, surgical treatment techniques are recognized that make useof a flaw in the absorption of foodstuffs, i.e. a shortening of the foodpassage and of digestive successes and techniques making use of agastric restriction that reduces the size of the stomach. surgicaltechniques implicating a flaw in absorption are those implicating, forexample, a “by-pass” technique, or small intestine bypass, or even thoseimplementing a separation of the alimentary passage relative to thedigestive successes These surgical techniques are relatively major andmay give rise to severe complications, and this is the reason for whichthey are almost never used any more now.

Now the tendency is to use surgical techniques which make use of lessdrastic surgical interventions, such as gastric restriction involvingthe installation of a gastric ring.

These techniques are now in fairly common use, and for the most partthey use, as described for example in patent U.S. Pat. No. 5 074 868, aflexible band of elastomeric material designed to be implanted aroundthe stomach, forming a closed loop defining a fixed pre-established ringdiameter, thanks to a closure system. The body of the flexible bandcomprises a compression cavity or chamber, of variable volume, which islinked to an adjustment catheter allowing injection or extraction offluid in the compression chamber, so as to cause the internal diameterof the loop to vary, in order to change or adjust the diameter of thestoma. In this way, in combination with the pre-established and fixedring diameter, which allows adjustment of the stoma diameter andtherefore regulation of the quantity of food ingested.

These known devices generally offer satisfaction, but nevertheless havea certain number of drawbacks linked essentially to difficultiesstemming from the surgical interventions carried out after installationof the gastric ring. In effect, it has been shown that, in spite of thepossibility of being able to modify, to a certain extent, the diameterof the ring without major surgical intervention, thanks to the presenceof a miniature case implanted under the skin of the patient,installation of such rings may be accompanied by intolerance phenomena,accompanied for example by vomiting. This may be linked to variouscauses, and notably to too great a reduction in the diameter of thestoma, or even to an ineffective action of the ring, associated with toogreat a stoma diameter, or even merely an obstruction, infection orlocal or general inflammation.

This is the reason why it is often shown to be necessary to once againperform surgical intervention, either to relieve the patient, or toadjust or change the ring implanted previously. Such surgicalintervention is particularly severe and most often requires cutting ofthe ring by a surgeon, along with its changing and replacing.

Finally, such operations are difficult to carry out, difficult for thepatient to tolerate, and costly, all the more because they involvedestruction and replacement of a ring.

Along with these classic techniques, we also establish a progressive andgradual loss of pressure inside the ring, due to natural osmoticphenomena across the device wall. This necessitates regularinterventions in order to readjust the diameter of the ring andcontributes to the increased need for the constant surveillance of thepatient.

Finally, it has been established that it is possible to use a simplesyringe, generally filled with physiological water, to ensure diametricreadjustment of the ring by injecting liquid through a subcutaneous caseattached to the ring. This is an operation which, because of itssimplicity, can escape all medical inspection and be carried out by thepatient himself. Optimal safety and control conditions are not,therefore, fulfilled in the case of classical techniques.

To attempt to resolve these drawbacks, a solution has already beenproposed, such as that described in the patent application EP-0 876 808.This is a gastric ring that is adjustable in a non-invasive manner, withno patient discomfort, done by remote control, without invasive surgicalintervention, by an electromagnetic means implanted in the body of thepatient and mounted at least in part on the gastric ring. The meansimplemented comprise a control box, implanted in the ring and attachedto a fluid reservoir, which is also implanted in the body of thepatient. With the help of a pump controlled from outside the patient'sbody through electromagnetic means, it injects or withdraws fluid in thegastric ring in order to adjust its diameter. The entire device is underthe control of a means of external control, of the micro-computer type,equipped with an emitter-receiver radio, for example, under the controlof the practicing physician.

Such a device, of course, indicates an interesting and beneficialdevelopment for patients, but which nevertheless suffers from a certainnumber of drawbacks linked, in particular, to the need to implant thefluid reservoir directly into the body of the patient. This implantationis delicate and it is difficult to make it watertight, which couldpresent a danger to the patient. Moreover, such a device requires asource of internal energy, for example a battery, implanted in the bodyitself of the patient, which once again complicates surgicalintervention and especially confers a certain fragility upon the system,and could necessitate surgical intervention to change the battery.

OBJECTS ADN SUMMARY OF THE INVENTION

Consequently, the invention seeks to remedy the various drawbacks listedabove, and to propose a new surgical ring that has a reversible diametercontrol system. This system is particularly simple, reliable andeffective, notably with regard to precision and efficiency, such that itcan be integrated into a remote control system that does not requiresignificant control energy.

Another object of the invention seeks to propose a new surgical ring,notably gastric, whose mechanical control is particularly precise.

Another object of the invention seeks to propose a new surgical ring,notably gastric, which is of a circular shape during use, all the whileoffering great control safety.

Another object of the invention seeks to propose a new surgical ring,notably gastric, which allows implementation of mechanical means thatare particularly well tested and resistant, so as to obtain a gastricring of great sturdiness and good longevity.

Another object of the invention seeks to propose a new surgical ring,notably gastric, which, while allowing good control of the variation ofthe diameter of the ring, is likely to minimize intolerance phenomena inthe patient.

Another object of the invention seeks to propose a new surgical ring,notably gastric, whose control system is particularly thrifty withregard to energy usage.

Another object of the invention seeks to propose a new gastric ring ofgreatly reduced bulk, which allows easy implantation in the patient'sstomach.

Another object of the invention seeks to propose a new surgical ring,notably gastric, which allows good division of all closure forces of thering on the stomach.

Another object of the invention seeks to propose a new system ofrestriction and remote control of ingestion of food into the stomach ofa patient that is particularly effective, very sturdy and long-lived,while at the same time requiring relatively low supply energy.

The objects assigned to the invention are achieved with the help of asurgical ring, designed to be implanted in the body of a patient aroundbiological organs having a pouch or a duct so as, on the one hand, toform a closed loop between its two extremities, thus forming a first andsecond extremities and, on the other hand, reduce the diameter of theopening of the biological organ when it is tightened by the ring, saidring comprising a system to reversibly control the variation in itsdiameter, said system comprising a flexible filiform element,characterized in that:

-   -   said flexible filiform element is inserted longitudinally with        possibility of sliding into the material forming the body of the        ring, substantially between the first and second extremities, in        order to define a fixed portion united with the first extremity        and a free portion, functionally associated with an actuator        mounted on the ring, near the second extremity, such that the        actuator may ensure reversible translation of the flexible        filiform element in order to obtain a variation associated with        the diameter of the ring,    -   said free portion features a means of force cooperation with the        actuator, said means of force cooperation being formed of a        screw thread pitch.

The objects assigned to the invention are also achieved with the help ofa system of restriction and remote control of the ingestion of food intothe stomach of a patient, comprising:

-   -   A gastric ring, as defined previously and comprising, as an        actuator, an electric motor that is linked to a receiving        antenna in order to receive a control and power signal.    -   An emitting antenna arranged outside the patient, in order to        send a control and power signal to the receiving antenna, said        emitting antenna being functionally linked to a control        interface.

BRIEF DESCRIPTION OF THE DRAWING

Other objects and advantages of the invention will become more apparentupon reading the attached description, as well as with the help of theattached drawings, which are given strictly for illustration andinformation purposes, in which:

FIG. 1 shows, according to a longitudinal section view, an example of afirst variation of embodiment of a gastric ring in compliance with theinvention.

FIG. 2 shows a transverse section view of the gastric ring shown in FIG.1, said cutaway being made according to line II-II of FIG. 1.

FIG. 3 shows, according to a longitudinal section view, a secondvariation of embodiment of a gastric ring in compliance with theinvention.

FIG. 4 shows the transverse cross section of the gastric ringillustrated in FIG. 3, said section being made along line IV-IV of FIG.3.

FIG. 5 shows, according to a perspective view and a partial longitudinalsection view, an example of embodiment of a gastric ring in compliancewith the invention and corresponding to the second variation ofembodiment illustrated in FIG. 3, said ring being equipped with areceiving antenna in the extended position.

FIG. 6 shows, according to a perspective view, a gastric ring identicalto that illustrated in FIG. 5, the receiving antenna being in theextended, functioning position.

FIG. 7 illustrates, according to a perspective view, a gastric ring incompliance with the invention, illustrating the extended electricalconnection wires.

FIG. 8 shows, according to a transverse section view, the collapsedposition of the ring's receiving circuit with the receiving antenna.

FIG. 9 shows, according to a transverse section view, the receivingcircuit with its antenna in the extended position.

FIG. 10 shows, according to a partial perspective view, an embodimentdetail of the flexible filiform element in compliance with theinvention, and whose function is to adjust the ring diameter.

MORE DETAILED DESCRIPTION

In the following description, reference will be made, solely as anexample, to a gastric ring concepted for implantation around the stomachin order to reduce the diameter of opening of the stoma, or around theesophagus. In effect, the invention is in no way limited to thisapplication, and on the contrary seeks to cover other surgical rings,such as those used to treat urinary or fecal incontinence, or those usedaround blood vessels in order to regulate blood flow.

In the case of treatment of urinary continence, the ring will beimplanted around the bladder or urinary tracts, and in the case of fecalincontinence, it will be implanted around gastrointestinal tracts, andnotably around anal structures of the intestine.

FIGS. 1 to 10 illustrate a gastric ring in compliance with theinvention, designed to be implanted around the stomach of a patient, byforming a substantially circular loop, in order to cause gastricrestriction by reducing the diameter of the opening of the stomach. Thegastric ring in compliance with the invention is shown in the form of aflexible tubular band, whose flexible and elastic envelope has a smoothsurface, making it atraumatic so that it is easily tolerated by thepatient and the tissues of the stomach. The band is made, for example,from elastomeric material.

The flexible tubular band comprises two extremities, respectively 1 and2, on which means of closure 9 are shaped and implanted (FIGS. 5 and 6).The last are intended to cooperate in such a way as to ensure latchingand closure of the ring around the stomach, in order to create a closedloop between the two extremities 1 and 2, thus forming, respectively, afirst and a second extremity.

The gastric ring in compliance with the invention is shown in the shapeof a torus of revolution, of cross-section, for example, that issubstantially cylindrical, delimited on the outside by a mono-layer ormulti-layer envelope 3. This envelope could advantageously be made of aprotective covering, for example, based on or made of silicone.

As shown in particular in FIGS. 1 and 3, the gastric ring in compliancewith the invention consists, advantageously, of a flexible filiformelement 4 having good flexibility and a good mechanical resistance. Itis inserted longitudinally, with possibility of sliding along theprincipal axis of symmetry of the cylinder, or of the main body of thering. Said element 4 occupies the cavity linking the first and secondextremities 1 and 2 and extends substantially between the first andsecond extremities 1 and 2, i.e. substantially all along the developedlength of the ring.

As shown in the figures, the flexible filiform element 4 is mounted soas to define a fixed portion 4 which is consolidated with the help of ameans of consolidation 6, which, for example, makes use of a retainingring and a washer, or any equivalent means, with the first extremity 1of the ring. The other terminal portion of the flexible filiform element4 which forms a free portion 7, i.e. that which might shift bytranslation relative to the fixed portion 5. Said free portion 7 isfunctionally associated with an actuator 8 mounted on the ring, near oron the level of the second extremity 2. Actuator 8 is used to transmitthe energy necessary to ensure, when it is activated, the reversibletranslation of the flexible filiform element 4 to the interior of thering, i.e. the reversible shift of free portion 7 relative to fixedportion 5, with a view to obtaining an associated change in the ring'sperimeter, i.e. an increase or reduction in its diameter.

Direct mounting of the actuator 8 on one of extremities 2 of the ringalso allows a significant gain in space and a good mechanicalefficiency.

Advantageously, the free portion 7, extending, for example, along alength on the order of a few centimeters, or along the entire length ofthe flexible filiform element, is provided with a means of forcecooperation 10 (FIG. 10) with actuator 8. This means 10 is designed toensure transmission of energy supplied by actuator 8 to the entireflexible filiform element 4, starting from its support point, consistingof the fixed portion 5.

Advantageously, and as shown in FIG. 10, the means of force cooperation10, consist of a screw thread pitch.

According to the invention, the flexible filiform element 4 hassufficient flexibility so that it can be adapted to the substantiallycircular shape of the ring, while at the same time being able totransmit the force necessary for adjustment of the ring diameter.Advantageously, the flexible filiform element 4 consists of a flexiblecore 11, preferably metal, for example of circular cross section, onwhich is fixed, and wound coaxially, for example over its whole length,at least one un-joined coil spring which comprises the screw threadpitch.

In a particularly ideal way, flexible filiform element 4 comprises twoun-joined coil springs which form the screw thread pitch, respectively,a first spring 12A, wound helicoidally along the flexible core 11, and asecond spring 12B of greater exterior diameter, such as that shown inFIG. 10, and preferably comprising coils 14 of rectangular transversesection 13, So as to delineate a flat external generatrix. Said firstspring 12A is interposed between coils 14 of the second spring 12B inorder to maintain a constant square screw thread pitch.

Thanks to this arrangement, it is possible to keep constantly a threadpitch that is substantially constant and effective, even in the case ofdeformation of the flexible filiform element 4. This confers a greatprecision and effectiveness on the device, while at the same time beinglow in energy costs required for its function by reason of the highefficiency of the transmission by a square screw thread pitch.

Thanks to this arrangement, it is possible to guarantee a stableadjustment position even when no energy is provided to the system.

The second spring 12B may be advantageously obtained by laser cutting ofa cylindrical hollow tube. Its sturdy mounting between loops 12D of thefirst spring 12A is done using longitudinal traction. The second spring12B is therefore naturally activated with an intrinsic elasticcompression force which tends to make the Loops jointed. This intrinsicforce is thrown down by loops 12D of the first spring 12A, against whichthey are supported. We also have the benefit of a constant feed despitethe natural and indispensable elasticity and flexibility of the flexibleelongated element 4.

Actuator 8 may be of any classical means known to the craftsman whichcould fit with the screw thread pitch so as to transmit movement to it.In a particularly ideal way, actuator 8 may be provided with a simplebolt which allows assurance of screw thread pitch drive. Actuator 8 may,in general, be by means of a motor, an electric or electromagneticmotor, or otherwise, without however deviating from the scope of theinvention.

As a variation of realisation not shown in the illustrations, it is ofcourse possible to replace the screw thread pitch described above by anyequivalent technical means and, for example, by a mesh rack on actuator8, featuring a gear or an equivalent means. We can also envision makingthe flexible filiform element 4 in the shape of a simple cable, drivenreversibly by an actuator 8 integrating a pulley.

As shown in the figures, the gastric ring in compliance with theinvention, generally speaking, whose body consists mainly of acompressible material 20 and which fills the interior of envelope 3.Flexible filiform element 4 is inserted longitudinally and substantiallyinto the compressible material 20, with the possibility of sliding, asshown in the example in FIGS. 2 and 4.

In a particularly ideal manner, compressible material 20 is ePTFE, whosecompressibility and stability characteristics in constriction areparticularly well suited to this type of application.

According to a first variation of embodiment, as shown in FIGS. 1 and 2,the ring in compliance with the invention consists of an envelope 3 madeof silicone material and of a thickness that is substantially constant,which comprises the watertight exterior covering of the ring. Theinterior covering of the ring is made exclusively of compressiblematerial 20, for example ePTFE, inside of which the flexible filiformelement 4 is inserted with a slight clearance.

Extremity 1 comprises a pouch 21, which for example is filled with glue,and in which is mounted and fixed, the fixed portion 5, with means ofconsolidation 6.

As shown in FIGS. 1 and 2, extremity 1 is provided with a tab 22 whichextends towards the exterior of the ring, and is designed to fit with acomplementary female element 23, which is integral to the same extremity1 of the ring. The ring constitutes closure means 9, which leads tolatching of the ring and forms, for example, a loop around extremity 2.

According to this first variation of production, the action of theactuator 8 on the flexible filiform element 4 transmits an actuatingforce according to one of the directions indicated by arrow Fillustrated in FIG. 1. The consequence of this is to compress orrelease, in a substantially longitudinal way, compressible material 20which translates by a variation associated with the ring's diameter,both internal and external, substantially in the manner of a slip knot.

The second variation of embodiment illustrated in FIGS. 3 and 4 differsfrom the one illustrated in FIGS. 1 and 2 only in the specificarrangement of the external envelope 3, whose dorsal periphery 25 isreinforced with a view to clipping the external radial extension orcentrifugal of the ring. This, on the contrary, favors internal radialor centripetal variation of the diameter of the ring. In this way, wefavor radial variation of the ring diameter at its internal periphery,which is opposite its dorsal periphery.

As shown, the dorsal periphery 25 may be made in the form of an externalenvelope 3 of which only the dorsal periphery has an allowance, i.e. anexternal dorsal thickness that is greater than the rest of the externalenvelope (FIG. 4). Alternatively, or complementarily, dorsal periphery25 may also be made using a polymeric material of greater hardness thanthe hardness of the rest of the polymer material envelope 3. It is alsoconceivable, as shown in FIG. 4, to provide for integrating, in thereinforced dorsal periphery 25, a reinforcing insert 26, preferablymetallic, extending over the majority of the ring's periphery betweencompressible material 20 and dorsal periphery 25. Advantageously, insert26 can have a shape memory that is substantially circular, in order toattain an elastic circular rest position of the ring.

Thanks to this arrangement, increase or reduction of the ring's diameteris limited to a reversible radian displacement, located at the level ofthe internal periphery of the ring opposite the dorsal periphery, whichtranslates into a variation of the ring's internal diameter in thecentrifugal or centripetal direction, according to the direction of thestress imparted to the flexible filiform element 4, indicated by one ofthe directions of arrow F.

The gastric ring in compliance with the invention is particularlyconcepted to be integrated into a system of restriction and remotecontrol of food ingestion in the stomach of a patient, in such a way asto be able to remotely control the variation of the ring's diameterwithout any invasive surgical intervention. To this end, actuator 8 isan electric motor which, advantageously, is linked to a subcutaneousreceiving circuit provided with a receiving antenna 30 (FIGS. 5 to 7)for reception of a radio frequency control and power signal, all ofwhich is designed to be implanted in the patient's body.

As illustrated notably in FIGS. 5 to 7, the electric motor isconsolidated with extremity 2, so that it can be located outside thering, since the electric motor is provided, in the standard manner, witha set of bearings and gears, which are functionally linked with anelectrical connection 31 to the receiving circuit antenna 30.

In this preferred application, the electric motor has no internalsources of supply at all, because its energy is provided by thereceiving circuit 30. This converts radio frequency waves received fromthe control unit through the exterior antenna, into a motor controlsignal and energy, ensuring its electrical supply. Receiving antenna 30is adapted and chose to receive a control signal and a power signal atthe same time.

The low energy requirement of the electric motor allows control ordersand activating energy to be sent by radio frequency to the motor,avoiding any need to have to implant an additional source of energy,such as a battery or battery cell, in the body of the patient.

As shown in FIG. 5, the electric motor is linked to the receivingantenna 30 by electrical connection 31, which is protected by aprotection duct 33. This ensures watertightness. At its extremity ismounted said receiving circuit, which comprises receiving antenna 30.The free portion 7 of the flexible filiform element is also integral toduct 33 in such a way as to achieve a perfectly protected assembly,watertight and which will irritate the surrounding tissues as little aspossible.

In a particularly ideal way, said receiving antenna circuit iselastically collapsible (FIGS. 8 and 9), so that the surgeon maymomentarily reduce the dimensions of the implantable part of the system,i.e. the ring, duct 33 and receiving antenna circuit 30. This enablesthe monoblock assembly to pass through a small-dimension trocar,preferably of a diameter less than, for example, 15 mm, in order tofacilitate implantation.

As shown in FIGS. 8 and 9, the collapsible receiving antenna circuit 30shall be advantageously but not necessarily flexible, either entirely,or at least in part, and shall consist of a flexible electronic circuit40, shown for example in the shape of a disk covered with a siliconeenvelope 41. This latter also serves as protection for electroniccomponents 42, connected and functionally linked to the antenna itselfof flexible circuit 40.

According to a particularly ideal version of the invention, thereceiving antenna circuit 30 shall be shown in the shape of a piece, forexample, in the shape of a disk that is collapsible onto itself,substantially according to the diameter of the disk as shown in FIGS. 5and 6.

Thanks to this arrangement and to the elasticity and flexibilityproperties of the selected materials, it is also possible, starting fromthe extended position of antenna circuit 30, as shown in FIGS. 6 and 9,to collapse the antenna circuit 30 along its diameter. This way itoccupies a restricted volume (FIG. 8), which allows its insertion into acircular trocar, whose shape 45 is shown in the dotted line in FIG. 8.

The system of restriction and remote control in compliance with theinvention also consists of an emitting antenna (not shown in theillustrations), arranged outside the patient to send a control and powersignal to receiving antenna 30 Said emitting antenna is itself linked tothe function of a control interface, such as a PC or any otherequivalent means at the disposal of the treating physician

During its use and, once the gastric ring in compliance with theinvention has been implanted, with its receiving circuit, featuringantenna 30 in the extended position, in the patient's body, thepracticing physician may position the emitting antenna in theface-to-face position with the receiving antenna 30 on the skin of thepatient. The doctor may then send a control and power signal in thedirection of the receiving antenna 30, to transmit to it, at the sametime, energy required to activate actuator 8 and, at the same time,control the direction of its shift.

Thanks to the system of restriction and remote control in compliancewith the invention, it is thus possible to vary the diameter of thegastric ring without having to undertake invasive surgical intervention,and this variation may be carried out at will, because multiple controlcycles may be carried out at regular or irregular intervals, solelyunder the control of the treating physician.

The system has been shown to be particularly reliable, because only thetreating physician has the control box, comprising the emitting antenna,which allows him to exert total control over the diameter adjustment.The patient cannot, therefore, have free access to any means ofadjusting the diameter of the ring

Therefore, the invention involves a new surgical and therapeutictreatment procedure, implementing a system of restriction and remotecontrol of food ingestion according to the invention.

1-18. (canceled)
 19. Apparatus for regulating the functioning of apatient's organ or duct, comprising: an elongated member having firstend and second ends, the elongated member having a substantially smooth,atraumatic ventral surface; a clip disposed on the first end of theelongated member, the clip configured to engage the second end of theelongated member so that the elongated member forms a loop around theorgan or duct; a flexible element slidably disposed within the elongatedmember, the flexible element defining a helical screw thread; and atelemetrically-controlled actuator disposed on the second end of theelongated member, the actuator having a nut that engages the helicalscrew thread, operation of the actuator causing the nut to draw thehelical screw thread therethrough, whereby the flexible elementconstricts the loop against the patient's body organ or duct.
 20. Theapparatus of claim 19 wherein the elongated member comprises aprotective covering.
 21. The apparatus of claim 19 wherein the apparatusis configured for laparoscopic introduction.
 22. The apparatus of claim21 wherein the clip further comprises a tab extending from the first endof the elongated member, the tab configured to pass through and engagean aperture disposed in the second end of the elongated member.
 23. Theapparatus of claim 19 wherein a portion of the flexible elementcomprises a spring.
 24. The apparatus of claim 23 wherein the helicalscrew thread comprises: a core wire; a first helical spring disposed onthe core wire, the helical spring having a square transverse profile;and a second helical spring interwound with the first helical spring todefine a pitch of the first helical spring and to permit flexion of thehelical screw thread, while maintaining the pitch substantiallyconstant.
 25. The apparatus of claim 19 wherein the elongated membercomprises an elongated tube of compressible material that renders theventral surface of the elongated member compressible.
 26. The apparatusof claim 25 wherein the compressible material is ePTFE.
 27. Theapparatus of claim 19 wherein the telemetrically-controlled actuatorfurther comprises: an electric motor; a gear transmission coupling thenut to the electric motor; an antenna; and an electronic circuitelectrically coupled to the antenna and the electric motor.
 28. Theapparatus of claim 27 wherein the antenna and electronic circuit aredisposed within an elastomeric envelope.
 29. The apparatus of claim 28wherein the elastomeric envelope has a substantially flat profile aftersubcutaneous deployment.
 30. The apparatus of claim 29 wherein theelectronic circuitry and the antenna are collapsible.
 31. The apparatusof claim 20 wherein the dorsal periphery of the elongated member isreinforced to prevent diametral expansion of the dorsal periphery. 32.The apparatus of claim 31 wherein a dorsal thickness of the protectiveenvelope is greater than a ventral thickness of the protective envelope.33. The apparatus of claim 31 wherein a dorsal hardness of theprotective envelope is greater than a ventral hardness of the protectiveenvelope.
 34. The apparatus of claim 31 further comprising a reinforcinginsert.
 35. The apparatus of claim 19 wherein the elongated membercomprises a gastric ring designed to be implanted around a patient'sstomach or esophagus.
 36. The apparatus of claim 19 wherein theelongated member comprises a ring designed to be implanted around thebladder or urinary tracts, or around gastro-intestinal tracts or aroundblood vessels.
 37. The apparatus of claim 19 further comprising anemitting antenna disposed outside the patient and configured to send acontrol and power signal to the antenna, the emitter antenna beingfunctionally linked to a control interface.
 38. Apparatus for gastricbanding of a patient's stomach, comprising: an elongated member havingfirst end and second ends, the elongated member having a compressibleventral surface and a substantially rigid dorsal periphery andconfigured to be formed into a loop around a portion of a patient'sstomach; an electric motor disposed on the second end of the elongatedmember; a nut actuator coupled to the electric motor; a flexible elementslidably disposed within the elongated member, the flexible elementdefining a helical screw thread, the flexible element having a fixed endcoupled to the first end of the elongated member and a free end thatengages and extends through the nut actuator, wherein operation of thenut actuator draws the helical screw thread through the nut actuator andcauses the flexible element to vary a diameter of the loop.
 39. Theapparatus of claim 38 wherein a portion of the flexible element furthercomprises a spring.
 40. The apparatus of claim 39 wherein the helicalscrew thread comprises: a core wire; a first helical spring disposed onthe core wire, the helical spring having rectangular transverse profile;and a second helical spring interwound with the first helical spring todefine a pitch of the first helical spring, the second helical springhaving first and second ends operatively coupled to the core wire end tomaintain the pitch substantially constant.
 41. The apparatus of claim 38where the elongated member is reinforced on the dorsal periphery toprevent diametral expansion of the dorsal periphery of the elongatedmember.
 42. The apparatus of claim 41 wherein the elongated membercomprises a reinforcing insert.
 43. The apparatus of claim 38 whereinthe elongated member comprises an elongated tube of compressiblematerial that renders the ventral surface of the elongated membercompressible.
 44. The apparatus of claim 38 wherein the elongated memberfurther comprises a protective covering.
 45. The apparatus of claim 44wherein the protective covering provides a smooth, atraumatic surfacefor contacting the patient's stomach.
 46. The apparatus of claim 38further comprising: an antenna; and an electronic circuit electricallycoupled to the antenna and the electric motor.
 47. The apparatus ofclaim 46 wherein the antenna and electronic circuit are disposed withinan elastomeric envelope.
 48. The apparatus of claim 47 wherein theelastomeric envelope has a substantially flat profile after subcutaneousdeployment.
 49. The apparatus of claim 48 wherein the electroniccircuitry and the antenna are collapsible.
 50. The apparatus of claim 46further comprising an emitting antenna that transmits commands to theelectronic circuit via the antenna.
 51. The apparatus of claim 38wherein the apparatus is configured for laparoscopic introduction. 52.The apparatus of claim 38 further comprising a clip disposed on thefirst end of the elongated member, the clip configured to engage thesecond end of the elongated member.
 53. The apparatus of claim 52wherein the clip further comprises a tab extending from the first end ofthe elongated member, the tab configured to pass through and engage anaperture disposed in the second end of the elongated member.